bzb948--Welcome to the boards!
Regarding TSH, well, this is questionable, if you test later in the day and have eaten a meal('s), you are more likely
to have a lower TSH levels rather than if you tested in the morning while fasting.
Also, the type of thyroid meds that you are taking could change your results. If you are on a T-4 (only) it stays in the system and then the TSH results are based on ~weeks~ of dosing verses T-3's short duration.
My doctor never says to fast (I' on Synthroid) or go in the morning, however, I *think* it's a good practice to do so from what I have read. My last TSH, F T-4, I was just unable to get out in the morning so I went late in the afternoon and had of course eaten meals by then. It didn't seem to lower my results according to other labs that I have recently had, they were pretty consistent and those were taken in the morning, I try.
As far as anemia goes if you are doing an iron panel I would fast, but if it is a standard CBC and Ferritin, I would not, it is not necessary and does not change results. None of my doctors have ever had me fast for any type of iron testing.
I would TRY to have all testing done in the morning before
any food or supplements, just to get more optimal results. A simple short overnight fast is all that is required, nothing after midnight. Take care and hope that helps you. FLFG